基于天然气压力能利用的沼气提纯并网方法

Purification and Grid-connected Method of Biogas Based on Natural Gas Pressure Energy Utilization

以基于天然气管道压力能利用的沼气提纯方法为研究对象,利用HYSYS过程模拟软件,选择单位能耗作为评价指标,在高压管道天然气体积流量一定的情况下,分析了天然气进口压力、天然气出口压力、待处理沼气流量、待处理沼气压力对单位能耗的影响。结果表明:天然气体积流量为100×10^(4) m^(3)/d、进口压力为4 MPa、出口压力为0.4 MPa的情况下,可以将体积流量为30×10^(4) m^(3)/d、压力为200 kPa、甲烷摩尔分数为63.5%的沼气提纯至甲烷摩尔分数为95.4%,单位能耗为0.0104 kW·h/m^(3)。当其他条件一定时,天然气进口压力升高,单位能耗下降;天然气出口压力升高,单位能耗升高;待处理沼气流量增加,单位能耗增加;待处理沼气压力升高,单位能耗下降。

Taking the biogas purification method based on the utilization of pressure energy in natural gas pipeline as the research object,using HYSYS process simulation software and selecting unit energy consumption as the evaluation index,the effects of natural gas inlet pressure,natural gas outlet pressure,biogas flow to be treated and biogas pressure to be treated on unit energy consumption are analyzed under the condition of constant volume flow rate of natural gas in high-pressure pipeline.The results show that when the volume flow rate of natural gas is 100×10^(4) m^(3)/d,the inlet pressure is 4 MPa,and the outlet pressure is 0.4 MPa,the biogas with the volume flow rate of 30×10^(4) m^(3)/d,pressure of 200 kPa and methane molar fraction of 63.5%can be purified to the methane molar fraction of 95.4%,and the unit energy consumption is 0.0104 kW·h/m^(3).When other conditions are constant,the unit energy consumption decreases with increase of natural gas inlet pressure;the unit energy consumption increases with increase of natural gas outlet pressure;the unit energy consumption increases with increase of the flow rate of biogas to be treated,and the unit energy consumption decreases with increase of the pressure of biogas to be treated.